A six-year-old boy who was accidentally shot in the head by a four-year-old playmate has died from his wounds, authorities said.

Ocean County prosecutor's office spokesman Al Della Fave confirmed Brandon Holt had died but said he could not provide further details. Toms River police Chief Michael Mastronardy said Holt was pronounced dead on Tuesday, nearly 24 hours after the shooting occurred in a neighbourhood that residents described as "very quiet."

Prosecutor Joseph Coronato, speaking earlier at a news conference, said the boy got the .22-calibre rifle from his home and it discharged accidentally on Monday evening. The children, whose families live in the neighbourhood, were about 15 yards apart.

The younger boy's mother called the emergency dispatcher to report the shooting, Mr Coronato said.

Mr Coronato said it was too early in the investigation to know whether anyone would be charged. He would not say who owned the gun or speculate on how the four-year-old got it.

Mr Mastronardy called the shooting tragic and said it affected the whole community, a sentiment shared by those who live there.

One resident said the two families had not lived in the neighbourhood for long and she did not know them well. "I'm sad for the children involved and their families, but I'm angry with whoever owns that gun and allowed a little child to get hold of it. A four-year-old can't load a gun," said Debi Coto, who lives a few doors down. "I had just been telling my sister how nice it is to see kids playing together and enjoying themselves, and then this happens."

Ms Coto said the four-year-old's mother seemed very upset in the minutes after the shooting and appeared to be trying to comprehend what had happened.

The shooting came just days after a four-year-old boy in Tennessee grabbed a loaded gun at a family cook-out and accidentally shot to death the wife of a sheriff's deputy and amid debate over gun control laws in the wake of December's Newtown, Connecticut, elementary school massacre.